P-68: Non-invasive characterization of arterial system function

Determination of the effects of disease processes and pharmacological perturbations on the arterial system by noninvasive measurements enhances our understanding of the drug interactions on arterial system performance. We have assembled 5 noninvasive instruments. The instruments are: BioZ (cardiac function); Colin (pulse wave velocities and ankle brachial index (ABI); HDI (calculated central and peripheral compliance based on analysis of the diastolic portion of the peripheral blood pressure curve, and cardiac function); SyphgmoCor (blood pressure curve and estimates of the central blood pressure curve, pressure augmentation based on analysis of the systolic portion of the central curve); and VascuMap (measured compliance of the brachial artery, ABI). Although each instrument's output variables are well described in the literature, no one data point adequately describes the arterial system in sufficient detail to characterize the arterial system function. In part, this is due to the scope of the measurement being too narrow, such as estimating a local variable (e.g. compliance) or too wide, such as estimating a global variable (e.g. pulse wave velocity). Either variable relies on statistical relationships to estimate the changes in the arterial system removed from the measurement site or within the measurement length. The combination of local and global data interpretation is more powerful in estimating arterial system changes. Interpretation of data from our instruments, including blood pressure, compliance, pulse wave velocity, augmentation and cardiac output and stroke volume, with each data point from at least 2 instruments (except pulse wave velocity) has increased our insight of the character and degree of changes in hypertensive patients and of specific classes of hypertensive agents on the arterial system function. We are cataloging these variables in normal and hypertensive states treated with and without blood pressure control and grouped by demographic characteristics. Separate and specific ongoing studies using more invasive procedures to characterize the degree of vascular disease are then correlated with the noninvasive variables. Male and female variable ranges are listed in the Table. (See Figure) Age MAP CO SVR PWV C1 C2 Males 28–82 86–149 3.1–10.8 807–3562 1188–2466 6.3–37.7 2.1–25 Females 25–83 76–164 2.4–8.1 926–4302 996–2770 3.2–21 0.8–12